A storage may be connected to a host, and perform a data access operation in response to a request from the host. For example, the storage may read data stored in the storage in response to a data read request from the host, and provide the read data to the host. Also, the storage may store data provided by the host in the storage, in response to a data write request from the host. The storage may use various media to store the data based on a type of data to be stored. A flash memory storage device such as a solid state disk (SSD) is a device for storing data using a flash memory.
The flash memory may erase data based on a block corresponding to a relatively large unit, and read or write the data based on a page corresponding to a relatively small unit. Similar to a block in which a number of erasures is limited, the flash memory may have various restrictions.
A flash transition layer (FTL) included in the flash memory storage device may provide a function of mapping to convert a logical address of data into a physical address. The logical address of data may be used to determine data requested, by the host, to be read or written. The logical address of data may be a sector number. The physical address of data may be a location of data included in the storage. Similar to an existing storage device, the FTL may enable the flash memory storage device to read or write the data based on a sector unit.
The flash memory storage device may manage a data structure required to map a memory address. Also, the flash memory storage device may use a predetermined size as a unit of mapping. Korean Patent Publication No. 10-2010-0117560 published on Nov. 3, 2010 discloses a flash memory storage device for providing a set of pages, each having a different size.